## [1] "19170101" "19170102" "19170103" "19170104" "19170105" "19170106"
## Subset Sites
## [1] OJAI CA US
## Levels: OJAI CA US
Let’s choose the BARROW W POST W ROGERS AIRPORT AK US because the record is longer than the airport.
Creating a linear model and then evaluate the rate (slope).
##
## Call:
## lm(formula = TMAX ~ NewDate, data = LosAngeles)
##
## Residuals:
## Min 1Q Median 3Q Max
## -44.919 -9.415 -0.342 9.350 40.416
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 7.807e+01 6.640e-02 1175.888 < 2e-16 ***
## NewDate -2.658e-05 6.259e-06 -4.247 2.17e-05 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 12.41 on 35529 degrees of freedom
## (782 observations deleted due to missingness)
## Multiple R-squared: 0.0005074, Adjusted R-squared: 0.0004793
## F-statistic: 18.04 on 1 and 35529 DF, p-value: 2.172e-05
So, let’s figure out how to see how changes happen for individual months.
## Month Year TMAX YEAR MONTH NewDate
## 1 01 1917 7.069547 1917 1 1917.000
## 2 02 1917 8.784908 1917 2 1917.083
## 3 03 1917 7.809974 1917 3 1917.167
## 4 04 1917 8.435284 1917 4 1917.250
## 5 05 1917 6.535758 1917 5 1917.333
## 6 06 1917 12.658194 1917 6 1917.417
below is sd
##
## Call:
## lm(formula = TMAX ~ NewDate, data = MonthlySD)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.5948 -1.3109 -0.1002 1.2044 7.9359
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 10.564453 3.578222 2.952 0.00322 **
## NewDate -0.001456 0.001819 -0.800 0.42385
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.802 on 1182 degrees of freedom
## (1 observation deleted due to missingness)
## Multiple R-squared: 0.0005412, Adjusted R-squared: -0.0003043
## F-statistic: 0.6401 on 1 and 1182 DF, p-value: 0.4238
##
## Call:
## lm(formula = TMAX ~ YEAR, data = MonthlyMean[MonthlyMean$Month ==
## "04", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -10.1433 -2.5047 -0.0938 2.8245 8.0180
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 21.6564 25.9442 0.835 0.4059
## YEAR 0.0267 0.0132 2.023 0.0458 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 3.75 on 96 degrees of freedom
## Multiple R-squared: 0.0409, Adjusted R-squared: 0.03091
## F-statistic: 4.094 on 1 and 96 DF, p-value: 0.04582
##
## Call:
## lm(formula = TMAX ~ YEAR, data = MonthlyMean[MonthlyMean$Month ==
## "07", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -8.9677 -2.0630 -0.1102 2.3523 8.7120
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 191.52739 22.20627 8.625 1.24e-13 ***
## YEAR -0.05114 0.01129 -4.529 1.69e-05 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 3.238 on 97 degrees of freedom
## Multiple R-squared: 0.1745, Adjusted R-squared: 0.166
## F-statistic: 20.51 on 1 and 97 DF, p-value: 1.69e-05
##
## Call:
## lm(formula = TMAX ~ YEAR, data = MonthlyMean[MonthlyMean$Month ==
## "08", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -6.8232 -1.5971 -0.0065 1.5255 8.5973
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 134.19879 20.15496 6.658 1.61e-09 ***
## YEAR -0.02162 0.01025 -2.109 0.0375 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.958 on 98 degrees of freedom
## Multiple R-squared: 0.04343, Adjusted R-squared: 0.03367
## F-statistic: 4.449 on 1 and 98 DF, p-value: 0.03746
##
## Call:
## lm(formula = TMAX ~ YEAR, data = MonthlyMean[MonthlyMean$Month ==
## "11", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -6.8244 -3.3259 0.3259 2.7188 10.2763
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 163.69455 27.98160 5.85 6.65e-08 ***
## YEAR -0.04539 0.01423 -3.19 0.00192 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 4.08 on 97 degrees of freedom
## Multiple R-squared: 0.09493, Adjusted R-squared: 0.0856
## F-statistic: 10.17 on 1 and 97 DF, p-value: 0.001919
##
## Call:
## lm(formula = TMAX ~ YEAR, data = MonthlyMean[MonthlyMean$Month ==
## "12", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -7.9694 -3.1011 -0.3825 3.0747 9.2401
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 137.85146 27.48570 5.015 2.42e-06 ***
## YEAR -0.03572 0.01398 -2.555 0.0122 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 3.958 on 96 degrees of freedom
## Multiple R-squared: 0.06365, Adjusted R-squared: 0.0539
## F-statistic: 6.526 on 1 and 96 DF, p-value: 0.0122
## Month Year TMIN YEAR
## 1 01 1917 34.58065 1917
## 2 02 1917 35.92857 1917
## 3 03 1917 33.35484 1917
## 4 04 1917 39.46667 1917
## 5 05 1917 41.09677 1917
## 6 06 1917 51.60000 1917
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "01", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -8.5486 -1.7755 -0.1755 1.3592 7.8665
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -26.78993 19.92827 -1.344 0.18195
## YEAR 0.03183 0.01013 3.142 0.00222 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.948 on 98 degrees of freedom
## Multiple R-squared: 0.09151, Adjusted R-squared: 0.08224
## F-statistic: 9.871 on 1 and 98 DF, p-value: 0.00222
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "03", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -5.073 -1.373 -0.519 1.671 6.960
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -21.363213 17.456061 -1.224 0.224012
## YEAR 0.031190 0.008879 3.513 0.000678 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.523 on 96 degrees of freedom
## Multiple R-squared: 0.1139, Adjusted R-squared: 0.1047
## F-statistic: 12.34 on 1 and 96 DF, p-value: 0.000678
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "05", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -5.6486 -1.6267 0.0623 1.6795 6.4054
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -5.887086 16.532669 -0.356 0.72256
## YEAR 0.027011 0.008409 3.212 0.00179 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.39 on 96 degrees of freedom
## Multiple R-squared: 0.09704, Adjusted R-squared: 0.08764
## F-statistic: 10.32 on 1 and 96 DF, p-value: 0.001794
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "06", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -5.3810 -1.2987 0.0021 1.4953 5.1190
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -23.090329 14.389683 -1.605 0.112
## YEAR 0.037559 0.007318 5.132 1.47e-06 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.095 on 97 degrees of freedom
## Multiple R-squared: 0.2136, Adjusted R-squared: 0.2055
## F-statistic: 26.34 on 1 and 97 DF, p-value: 1.47e-06
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "07", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -5.7796 -1.6199 -0.1003 1.7751 8.3318
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -14.601690 17.259527 -0.846 0.399631
## YEAR 0.035276 0.008777 4.019 0.000116 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.516 on 97 degrees of freedom
## Multiple R-squared: 0.1427, Adjusted R-squared: 0.1339
## F-statistic: 16.15 on 1 and 97 DF, p-value: 0.0001155
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "08", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.8051 -2.0273 -0.2833 2.0279 7.7257
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -10.458953 17.113818 -0.611 0.542521
## YEAR 0.033074 0.008702 3.801 0.000251 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.512 on 98 degrees of freedom
## Multiple R-squared: 0.1285, Adjusted R-squared: 0.1196
## F-statistic: 14.45 on 1 and 98 DF, p-value: 0.0002506
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "09", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -5.1896 -1.8215 0.0521 1.6751 9.3185
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -24.61825 18.66327 -1.319 0.19
## YEAR 0.03916 0.00949 4.127 7.72e-05 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.739 on 98 degrees of freedom
## Multiple R-squared: 0.1481, Adjusted R-squared: 0.1394
## F-statistic: 17.03 on 1 and 98 DF, p-value: 7.723e-05
##
## Call:
## lm(formula = TMIN ~ YEAR, data = MonthlyMeanTMIN[MonthlyMeanTMIN$Month ==
## "10", ])
##
## Residuals:
## Min 1Q Median 3Q Max
## -6.1782 -1.7592 -0.3477 1.8006 6.4333
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -9.124970 18.153567 -0.503 0.61635
## YEAR 0.028483 0.009232 3.085 0.00265 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.647 on 97 degrees of freedom
## Multiple R-squared: 0.08936, Adjusted R-squared: 0.07997
## F-statistic: 9.518 on 1 and 97 DF, p-value: 0.002651
Precipiation might depend more on the departure from the mean (often referred as as normal, whatever that means!). I think it’s worth pursuing, but haven’t finished the analysis yet.
First, we need a “mean” – The IPCC uses 1961-1990 as a norm, I don’t know what is the standard for California, so we should look that up.
Second, we need to remove the missing values and evalaute which years have complete years. If you are missing rainy months, then the whole year should be thrown out – but what about partial years in the drought season?
Third, we will need to decide what level of aggredation – monthly, yearly, etc.
Fourth, in CA the water year starts in Oct 1. Should we follow the same convention?
A yearly mean, based on the annual sum for the entire records. Not sure this is appropriate.
Figure has points of the yearly sum of rainfall and the blue line mean. The greenline is the trend and red line is a five year running average, I think! I am still trying to understand what the code is doing.
## [1] 0.2 0.2 0.2 0.2 0.2
The model suggests that the precipitation is declines at a rate of -0.0119165 cm yr\(^{-1}~\), or -0.12 cm decade\(^{-1}\).
##
## Call:
## lm(formula = PRCP ~ YEAR, data = YearlySum)
##
## Residuals:
## Min 1Q Median 3Q Max
## -15.517 -6.829 -2.899 5.132 27.802
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 43.06833 67.06418 0.642 0.522
## YEAR -0.01192 0.03409 -0.350 0.727
##
## Residual standard error: 9.989 on 99 degrees of freedom
## Multiple R-squared: 0.001233, Adjusted R-squared: -0.008856
## F-statistic: 0.1222 on 1 and 99 DF, p-value: 0.7274